This invention relates to an ink ribbon cassette used in a printer, etc.
Generally, an ink ribbon cassette used in a printer, etc., includes a chamber which accommodates an endless ink ribbon and a pair of arms, one extending from each end of the chamber. Most of the ink ribbon is accommodated in a zigzag folded state with a run of the ribbon being exposed through corresponding openings provided at the ends of the arms The inner wall of the ribbon accommodating chamber is formed horizontal relative to the exposed ink ribbon portion as viewed in a plan view.
In the conventional ribbon cassette mounted in a printer, when an accommodated ink ribbon is very long or highly impregnated with ink, the area of the ink ribbon contacting the inner surface of the ribbon chamber becomes larger, increasing the frictional resistance or the ink ribbon is likely to adhere to the inner surface of the ribbon chamber due to adhesiveness of the ink, so that the slidability of the ribbon is reduced. Therefore, the movement of the ribbon is likely to become bad and a large force is required to feed the ribbon to thereby require larger torque for driving the ribbon.
It is an object of this invention to improve the slidability of the ink ribbon and move the ribbon smoothly with low drive torque.